EP0359019B1 - Circuit de commande de suivi de piste pour un appareil à bande magnétique à balayage hélicoidal - Google Patents

Circuit de commande de suivi de piste pour un appareil à bande magnétique à balayage hélicoidal Download PDF

Info

Publication number
EP0359019B1
EP0359019B1 EP89115859A EP89115859A EP0359019B1 EP 0359019 B1 EP0359019 B1 EP 0359019B1 EP 89115859 A EP89115859 A EP 89115859A EP 89115859 A EP89115859 A EP 89115859A EP 0359019 B1 EP0359019 B1 EP 0359019B1
Authority
EP
European Patent Office
Prior art keywords
signal
level
pilot
track
reproduced
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP89115859A
Other languages
German (de)
English (en)
Other versions
EP0359019A3 (fr
EP0359019A2 (fr
Inventor
Hideto Sanda Seisakusho Miyazaki
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Publication of EP0359019A2 publication Critical patent/EP0359019A2/fr
Publication of EP0359019A3 publication Critical patent/EP0359019A3/fr
Application granted granted Critical
Publication of EP0359019B1 publication Critical patent/EP0359019B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
    • G11B5/58—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B15/00—Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function
    • G11B15/18—Driving; Starting; Stopping; Arrangements for control or regulation thereof
    • G11B15/46—Controlling, regulating, or indicating speed
    • G11B15/467—Controlling, regulating, or indicating speed in arrangements for recording or reproducing wherein both record carriers and heads are driven
    • G11B15/4673—Controlling, regulating, or indicating speed in arrangements for recording or reproducing wherein both record carriers and heads are driven by controlling the speed of the tape while the head is rotating
    • G11B15/4675—Controlling, regulating, or indicating speed in arrangements for recording or reproducing wherein both record carriers and heads are driven by controlling the speed of the tape while the head is rotating with provision for information tracking
    • G11B15/4676—Controlling, regulating, or indicating speed in arrangements for recording or reproducing wherein both record carriers and heads are driven by controlling the speed of the tape while the head is rotating with provision for information tracking using signals recorded in tracks disposed in parallel with the scanning direction
    • G11B15/4677—Controlling, regulating, or indicating speed in arrangements for recording or reproducing wherein both record carriers and heads are driven by controlling the speed of the tape while the head is rotating with provision for information tracking using signals recorded in tracks disposed in parallel with the scanning direction using auxiliary signals, i.e. pilot signals
    • G11B15/4678—Controlling, regulating, or indicating speed in arrangements for recording or reproducing wherein both record carriers and heads are driven by controlling the speed of the tape while the head is rotating with provision for information tracking using signals recorded in tracks disposed in parallel with the scanning direction using auxiliary signals, i.e. pilot signals superimposed on the main signal track

Definitions

  • the present invention relates generally to a helical scanning magnetic tape apparatus with a tracking control circuit, and more particularly to a tracking control circuit in a digital audio tape reproducing apparatus having a rotary head for helical scanning.
  • a digital audio tape recorder as one type of a digital audio apparatus comprises plural magnetic heads mounted on a rotary member placed in a rotary cylinder on which a magnetic tape is wound and is transported thereby. and the magnetic heads run on the magnetic tape in a direction which is oblique with respect to the direction along the length of the magnetic tape.
  • FIG.10 is a plan view of an example of a conventional magnetic tape transporting mechanism.
  • a rotary cylinder 1 rotates in the direction of arrow A.
  • a magnetic tape 4 which is drawn from a cassette 5 is wound around the peripheral region of about 90° of central angle of the rotary cylinder 1 by means of two guide pins 6 and 7, and is transported in the direction of arrow B by a driving capstan 9 and a pinch roller 8.
  • Two magnetic heads 2 and 3 mounted on a rotary head holder are arranged at the periphery of the rotary cylinder 1 so that each head tip slightly protrudes from the peripheral surface of the cylinder 1.
  • FIG.11 is a plan view of the magnetic tape 4 showing recorded tracks.
  • the tracks are inclined, as shown by an arrow C, relative to the transporting direction D of the magnetic tape 4.
  • tracks T2 are formed by the magnetic head 2 and tracks T3 are formed by the magnetic head 3.
  • tracking servo means is provided in the transporting device of the magnetic tape 4.
  • An automatic track finding method (abbreviated in general as ATF) is employed for the tracking servo means.
  • the ATF method when a digitalized signal is recorded on the track, a predetermined ATF signal is recorded on a start region and an end region of each track. Allocation of the ATF signal in the normal track mode is illustrated by FIG.12.
  • the ATF signal is composed of a pilot signal P and a synchronizing signal S which have a lower frequency than the digitalized signal of data.
  • the allocation pattern of the ATF signal is standardized and is repeated every four tracks on the magnetic tape 4.
  • the magnetic head 2 traces the track T2 in the direction of arrow E and detects early pilot signals P A , P B and P C and the synchronizing signal S.
  • a signal as shown by FIG.13(a), FIG.13(b) or FIG.13(c) is obtained by amplifying the detected signal of the pilot signal P A , P B or P C with an amplifier and then passing it through a low-pass filter.
  • FIG.13(a) When the magnetic head 2 accurately traces the track T2, a signal shown by FIG.13(a) is output.
  • the wave form P a shows the detected signal of the pilot signal P A
  • the waveforms P b and P c show the crosstalks of the pilot signals P B and P C , respectively. Since the center C H of the magnetic head 2 is on the center line C L of the track T2, the output level P1 of the wave form P b is equal to that of the wave form P c .
  • the level P1 of the wave form P b is lower than the level P2 of the wave form P c in a similar manner.
  • the difference between the levels P1 and P2 represents a deflected value of the magnetic head from the track T2, and a tracking error signal corresponding to the deflected value is obtained.
  • FIG.14 represents a level of a tracking error signal versus the deflected angle value.
  • a deflected angle of the abscissa is zero degree.
  • the center CH of the head 2 is on a center line of a neighboring track T3
  • the deflected angle is +180° or -180°. Then, the ordinate designates the level of the tracking error signal corresponding to the difference between the levels P1 and P2.
  • the levels P1 or P2 of the pilot signals P B and P C are detected in synchronism with synchronizing signals SP1 and SP2, respectively.
  • the synchronizing signals SP1 and SP2 are created on the basis of the synchronizing signal S of the ATF signal.
  • FIG.15 is a block diagram of a tracking control circuit for creating the tracking error signal in the prior art.
  • the detected signal of the magnetic head 2 or 3 is amplified by an amplifier 11 and is applied to a low-pass filter 15.
  • the higher frequency component including digitalized signal of data and the synchronizing signal S is eliminated by the low-pass filter 15.
  • the output signal of the low-pass filter 15 is applied to an envelope detecting circuit 16, and envelopes of the pilot signals P A , P B and P C are detected.
  • the amplified synchronizing signal S is separated from other signals by a band-pass filter 12, and then the zero level of the synchronizing signal S is detected by a zero-cross comparator 13.
  • a synchronizing signal generator 14 generates the synchronizing signals SP1 and SP2 on the basis of the output of the zero cross comparator 13.
  • the synchronizing signal SP1 is applied to a sample-and-hold circuit 17 and the level P1 of the pilot signal P B is detected. Then the value of the level P2 is subtracted from the value of the level P1 at an adder 18, and a resultant value is held by a sample-and-hold circuit 19 in synchronism with the synchronizing signal SP2.
  • the resultant value is the value of the tracking error signal.
  • the tracking error signal is applied to a tracking servo means. This is generally understood by the man skilled in the art and therefore is not described in greater details.
  • a characteristic of the level of the tracking error signal seriously deviates from a normal characteristic shown by a solid line L2 in FIG.16 due to an unbalance between sensitivities of the respective magnetic heads 2 and 3 or a variation of characteristics of the magnetic tape.
  • Various deviated characteristics of the level of the tracking error signal are represented by a dashed line L1 or an alternate long and short dash line L3. Consequently, a tracking servo loop gain must be varied to meet the deviation, and hence stable servo operation can not be maintained.
  • FIG.17 A prior art of the tracking control circuit for improving the above-mentioned difficulty is disclosed in the Japanese published unexamined patent application Sho 62-214543 and is shown in FIG.17.
  • an automatic gain control circuit 21 (hereinafter abbreviated as AGC circuit) is provided between the amplifier 11 and the low pass filter 15.
  • an adder 22 for calculating the sum of the levels P1, P2 and P3 in synchronism with the synchronizing signals SP1, SP2 and SP3 is provided, and the output signal of the adder 22 is applied to the AGC circuit 21.
  • the synchronizing signal SP3 is created on the basis of the reproduced signal of a synchronizing signal S of a neighboring tack.
  • the gain of the AGC circuit 21 is controlled by the output signal of the adder 22, and fluctuation of the output of the magnetic heads 2 and 3 is compensated.
  • the characteristic of the level of the tracking error signal shown by the solid line L2 of FIG.16 can be maintained.
  • the normal track mode as shown in FIG.18(a) and the wide track mode as shown in FIG.18(b) are standardized.
  • the normal track mode is applicable to recording and reproducing by a consumer.
  • the wide track mode is applied to make prerecorded tapes which are recorded in factory.
  • the output levels of the magnetic heads 2 and 3 reproducing the pilot signals P A , P B and P C are constant within a range of deflected angle (from +120° to -120°, for example).
  • the characteristic of the level of the tracking error signal which is preferable to the normal track mode as shown by a dotted line L5 of FIG.19 and which is slightly different from an ideal characteristic represented by a solid ling L4
  • the characteristic of the level of the tracking error signal seriously changes as shown by a dotted line L7 of FIG.20 which is different from the ideal characteristics of the level of the tracking error signal L6.
  • An object of the present invention is to provide a helical scanning magnetic tape apparatus with a tracking control circuit in which stable tracking servo operation is maintained.
  • the helical scanning magnetic tape apparatus in accordance with the present invention comprises the features mentioned in claim 1.
  • respective pilot signals of both neighboring tracks of the actual reproducing track of a magnetic head are detected due to crosstalk effects, and a tracking error signal is created on the basis of a difference between the level of the detected respective pilot signals. Then the level of the tracking error signal is controlled by a signal including a pilot signal which is detected in reproducing step of other track.
  • FIG.1 is a circuit block diagram of a first embodiment of a tracking control circuit in accordance with the present invention.
  • Two magnetic heads 2 and 3 in a magnetic tape transporting mechanism shown in FIG.10 scan a magnetic tape 4.
  • the magnetic head 2 or 3 moves in the direction of arrow E along the magnetic tape 4 which is transported in the direction of arrow D as shown in FIG.12.
  • a reproduced signal S1 of the magnetic heads 2 and 3 is inputted into an amplifier 31 through an input terminal 30.
  • the reproduced signal S1 is composed of both the output signals of the magnetic heads 2 and 3 which are combined to one signal in a time sequence.
  • FIG.2(a) shows the reproduced signal S1.
  • a signal A is reproduced by the magnetic head 2 and a signal B is reproduced by the magnetic head 3.
  • the output of the amplifier 31 is applied to a low-pass filter 32 and a band-pass filter 39.
  • the low-pass filter 32 allows to pass only early pilot signals P A , P B and P C and later pilot signals P D .
  • P E and P F of the ATF signal as shown in FIG.12, and digitalized signals of data and a synchronizing signal S of the ATF signal are eliminated.
  • a reproduced pilot signal S2 in FIG.1 is composed of the reproduced signals of the pilot signals P A .
  • P B and P C and the waveform thereof is shown in FIG.13(a), 13(b) or 13(c).
  • the reproduced pilot signal S2 is applied to an envelope detector 33, and an envelope of the reproduced pilot signal S2 is detected.
  • FIG.2(b) shows the reproduced pilot signal S2.
  • letters a, f, i and j designate reproduced pilot signals of the actual track of each magnetic head 2 or 3.
  • letters b, c, d, e, g, h, k and l designate pilot signals reproduced from the pilot signals of neighboring tracks which are detected by crosstalk.
  • the reproduced pilot signals a, b, c, g, h and i are reproduced from the early pilot signals of tracks, and the reproduced pilot signals d, e, f, j, k and l are reproduced from the later pilot signals of the tracks.
  • the output of the envelope detector 33 is applied to a first sample-and-hold circuit 34, a third sample-and-hold circuit 42 and an adder 35.
  • the band-pass filter 39 allows to pass only the reproduced synchronizing signal S S of the synchronizing signal S.
  • the synchronizing signal S S is applied to a zero-cross comparator 40, and a zero-cross time point is detected.
  • the output of the zero-cross comparator 40 is applied to a synchronizing signal generator 41, and synchronizing signals SP1, SP2 and SP3 which serve as timing signals are generated on the basis of the zero-cross time points of the synchronizing signal S S .
  • the synchronizing signal SP1 is generated during the period of reproduction of the pilot signal P B due to crosstalk as shown in FIG.2(c) and FIG.13(a), and is applied to the first sample-and-hold circuit 34.
  • a level P1 of the reproduced signal of the pilot signal P B is held in the first sample-and-hold circuit 34.
  • the output of the first sample-and-hold circuit 34 is applied to a positive input of an adder 35.
  • the output of the envelope detector 33 is applied to a negative input of the adder 35.
  • the adder 35 a difference between the value of the level P1 and the output value of the envelope detector 33 is detected and is held in synchronism with the synchronizing signal SP2 which is supplied from the synchronizing signal generator 41 with a second sample-and-hold circuit 36.
  • the synchronizing signal SP2 is generated during the period of reproduction of the pilot signal P C as shown in FIG.2(d) and FIG.13(a). Consequently, the difference between the value of the level P1 and the value of the level P2 of the reproduced signal of the pilot signal P C is held in the second sample-and-hold circuit 36 of FIG.1.
  • the difference (P1-P2) is designated by “signal S3”, and is applied to an automatic gain control circuit 37 (hereinafter abbreviated as AGC circuit).
  • AGC circuit automatic gain control circuit 37
  • the level of the signal S3 is controlled at the AGC circuit 37 on the basis of a signal S6 which is elucidated hereinafter.
  • FIG.2(f) is a time chart of the signal S3.
  • a representation "b-c” represents the difference (P1-P2) between reproduced signals of the pilot signals P B and P C
  • a representation "d-e” represents the difference (P1-P2) between reproduced signals of the pilot signals P D and P E , for example.
  • the output of the envelope detector 33 is also applied to the third sample-and-hold circuit 42 which is controlled by the synchronizing signal SP3.
  • the synchronizing signal SP3 is generated during the period reproducing the pilot signal P A of the actual track of the magnetic head 2 as shown in FIG.2(e) and FIG.13(a). Consequently, the level of the output signal S4 of the third sample-and-hold circuit 42 is equal to the level P3 of the reproduced signal of the pilot signal P A . Then the signal S4 is applied to a negative input of an adder 44.
  • the time chart of the signal S4 is shown in FIG.2(g).
  • the signal S4 is also applied to a delay circuit 43 which is controlled by the synchronizing signal SP3.
  • the delay circuit 43 causes the signal 4 to be delayed by a time period between two consecutive reproduced pilot signals.
  • a delayed signal S5, as shown in FIG.2(h) is output from the delay circuit 43.
  • the delay time is equal to a time period between the pilot signals P A and P F .
  • the delay time is equal to a time period between the pilot signals P F and P B .
  • the signal S5 is applied to a positive input of the adder 44.
  • the signal representing the difference between the two values is designated as "S6" in FIG.2(i).
  • the signal S6 is applied to the AGC circuit 37, and the level of the signal S3 is controlled by the signal S6 and is output from an output terminal 38.
  • the output of the AGC circuit 37 is a tracking error signal which is applicable to the servo control system in a manner that will be familiar to one skilled in the art.
  • the representation "f-i” represents a difference between a reproduced signal level of the signal "f” of the actual track of the magnetic head 2 and a reproduced signal level of the signal "i” of the actual track of the magnetic head 3 as shown in FIGs. 2(b) and 2(i).
  • the reproduced signal levels of the signals g, h and f are lower than the reproduced signal levels of the signals d, e and i, respectively, and thus the difference "f-i" becomes a negative value.
  • the AGC circuit 37 is made to increase its gain by applying a negative control signal.
  • the gain of the AGC circuit 37 is increased by applying the negative signal according to the difference "f-i"
  • the output level of the AGC circuit 37 which is represented by the difference "g-h" (tracking error signal) increases.
  • the improved characteristic of the level of the tracking error signal shown in dotted lines meets an ideal characteristic shown in solid lines in the range of deflected angle from +120° to -120° .
  • stable servo control is realized without requiring any change of the gain of the tracking servo system.
  • FIG.5 is a circuit block diagram of a second embodiment of the present invention.
  • the output of the envelope detector 33 is inputted into the adder 45 which is controlled by the synchronizing signals SP1 and SP2.
  • the output of the adder 45 is applied to the positive input of the adder 46, and the output of the delay circuit 43 is applied to the other positive input thereof.
  • the output of the adder 46 is applied to the AGC circuit 37.
  • the adder 45 holds the output of the envelope detector 33 in synchronism with the synchronizing signals SP1 and SP2, and calculates a sum of levels P1 and P2. Then a signal S7 having the level of the sum is created as shown in FIG.6(g). The signal S7 is added to the signal S5 output from the delay circuit 43 by means of the adder 46, and a resultant signal S8 is created as shown in FIG.6(j). The signal S8 is applied to the AGC circuit 37 to control the gain.
  • the tracking error signal S3 is controlled by a sum of the level of the reproduced signal of the later pilot signal of a track detected during previous reproducing period, and the levels of the signals of the early pilot signals of both neighboring tracks of the next successive track which is presently in reproduction.
  • the tracking error signal S3 represented by the difference "g-h” is controlled on the basis of the signal S8 represented by the sum "f + g + h".
  • the AGC circuit 37 in this embodiment is made to vary its gain in inverse proportion to a level of a control signal applied thereto. Therefore the level of the tracking error signal S3 is inversely proportional to the level of the sum "f + g + h". For example, when the recorded level of the signal A is lower than that of the signal B, the level of the sum "f + g + h" is lowered. Consequently, the gain of the AGC circuit 37 increases, and the level of the tracking error signal S3 increases.
  • FIG.7 is a circuit block diagram of a third embodiment of the present invention.
  • an AGC circuit 47 is placed between the amplifier 31 and the low pass filter 32, and the output of the second sample-and-hold circuit 36 is the tracking error signal.
  • the output of the delay circuit 43 is applied to the AGC circuit 47, and the remaining circuit is identical with that of the first embodiment.
  • the signal S4 based on a later pilot signal is delayed by the delay circuit 43, and a control signal S5 is created.
  • the control signal S5 is applied to the AGC circuit 47 during reproduction of the subsequent track. According to the third embodiment, therefore, the signal S5 controls the AGC circuit 47 in a direction to reduce a difference between the respective reproduced levels of neighboring two tracks.
  • FIG.9 is a circuit block diagram of a fourth embodiment of the present invention.
  • the AGC circuit 37 receives the output of the second sample-and-hold circuit 36, and is controlled by the output of the delay circuit 43.
  • Difference of the fourth embodiment with respect to the first embodiment shown in FIG.1 is that the control signal S5 is directly inputted to the AGC circuit 37 from the delay circuit 43.
  • a signal reproduced due to crosstalk of pilot signals of neighboring tracks is not included in the control signal S5 which is applied to the AGC circuit, serious variation of the level of the tracking error signal can be prevented, even if the level of the tracking error signal S3 varies due to unstable contact between the head chip and the tape surface.
  • the fourth embodiment in a manner similar to the third embodiment, since the tracking error signal created depending on crosstalk of pilot signals of the neighboring tracks is controlled by a reproduced signal of the own track of the head, a serious variation of the tracking error signal is prevented. Moreover, the third and fourth embodiment is simplified in configuration in comparison with the first or second embodiment.

Landscapes

  • Adjustment Of The Magnetic Head Position Track Following On Tapes (AREA)

Claims (3)

  1. Appareil à bande magnétique à balayage hélicoïdal avec un circuit de commande de suivi de piste comprenant:
    au moins une tête magnétique (2, 3) pour reproduire un signal enregistré de pistes obliques d'une bande magnétique incluant, dans chaque piste, au moins un signal pilote court (PA à PF), et un signal de synchronisation court (S) étant agencé suivant une relation prédéterminée par rapport audit au moins un signal pilote,
    un premier moyen filtrant (32) pour faire passer lesdits signaux pilotes dudit signal reproduit,
    un moyen de détection d'enveloppe (33) pour détecter le niveau d'une enveloppe desdits signaux pilote qui ont passé à travers ledit premier moyen filtrant (32),
    un deuxième moyen filtrant (39) pour faire passer ledit signal de synchronisation (S) dudit signal reproduit,
    un générateur de signaux de synchronisation (41) pour créer des signaux de synchronisation (SP₁, SP₂, SP₃) sur la base dudit signal de synchronisation qui a passé à travers ledit deuxième moyen filtrant (39),
    un moyen de calcul (35) pour calculer pour une piste présente tracée par ladite tête magnétique un niveau de différence entre les niveaux respectifs desdits signaux pilotes enregistrés sur les deux pistes avoisinantes, lesdits niveaux respectifs détectés en synchronisation avec lesdits signaux de synchronisation (SP₁, SP₂) par ledit moyen de détection d'enveloppe de composants de diaphonie dans le signal reproduit par la présente piste, un circuit échantillonneur (36) pour maintenir ledit niveau de différence en synchronisation avec ledit signal de synchronisation (SP₂), l'appareil étant caractérisé par :
    un circuit à retard (43) pour retarder le niveau du signal pilote de ladite piste présente détecté par ledit moyen de détection d'enveloppe en synchronisation avec ledit signal de synchronisation (SP₃) et
    un circuit automatique de commande de gain (37) pour commander ledit niveau de différence émis par ledit moyen de calcul sur la base au moins dudit niveau retardé du signal pilote de la piste tracée précédent ladite présente piste.
  2. Appareil selon la revendication 1, dans lequel deux têtes magnétiques (2, 3) sont prévues pour tracer alternativement des pistes qui se suivent.
  3. Appareil selon la revendication 1 ou 2, dans lequel ledit circuit automatique de commande de gain (37) commande ledit niveau de différence sur la base de la somme des niveaux de la somme desdits niveaux respectifs desdits signaux pilote enregistrés sur les deux pistes avoisinantes, et ledit niveau retardé du signal pilote.
EP89115859A 1988-09-05 1989-08-28 Circuit de commande de suivi de piste pour un appareil à bande magnétique à balayage hélicoidal Expired - Lifetime EP0359019B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP221911/88 1988-09-05
JP63221911A JPH0740340B2 (ja) 1988-09-05 1988-09-05 ヘリカルスキャン方式テープ再生装置のトラッキング制御回路

Publications (3)

Publication Number Publication Date
EP0359019A2 EP0359019A2 (fr) 1990-03-21
EP0359019A3 EP0359019A3 (fr) 1991-09-04
EP0359019B1 true EP0359019B1 (fr) 1995-04-05

Family

ID=16774090

Family Applications (1)

Application Number Title Priority Date Filing Date
EP89115859A Expired - Lifetime EP0359019B1 (fr) 1988-09-05 1989-08-28 Circuit de commande de suivi de piste pour un appareil à bande magnétique à balayage hélicoidal

Country Status (5)

Country Link
US (1) US5003413A (fr)
EP (1) EP0359019B1 (fr)
JP (1) JPH0740340B2 (fr)
KR (1) KR920006621B1 (fr)
DE (1) DE68922051T2 (fr)

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3840291A1 (de) * 1988-11-30 1990-05-31 Broadcast Television Syst Verfahren und schaltungsanordnung zur wiedergabe von datensignalen
JPH02195560A (ja) * 1989-01-24 1990-08-02 Sony Corp 再生方法
US5251079A (en) * 1989-12-30 1993-10-05 Sony Corporation Tracking control circuit including gain correction control
US5359475A (en) * 1992-03-23 1994-10-25 Minnesota Mining And Manufacturing Company Air filter system for helical scanner drum with vented drum cover
JP3271210B2 (ja) * 1993-05-11 2002-04-02 ソニー株式会社 回転ヘッド型磁気記録再生装置
JPH06338106A (ja) * 1993-05-28 1994-12-06 Canon Inc トラッキング制御装置
JP3420286B2 (ja) * 1993-05-28 2003-06-23 キヤノン株式会社 記録再生装置
US6005741A (en) * 1993-05-28 1999-12-21 Canon Kabushiki Kaisha Reproducing apparatus using pilot signal crosstalk for tracking control and using pilot signals to eliminate a back lock condition
JPH06349159A (ja) * 1993-06-01 1994-12-22 Canon Inc トラッキング制御装置
KR0150809B1 (ko) * 1993-09-17 1998-10-15 모리시타 요이찌 정보재생장치
EP0823113A1 (fr) * 1995-04-28 1998-02-11 Deutsche Thomson-Brandt Gmbh Appareil d'enregistrement et de lecture de pistes en spirale de donnees
US5828514A (en) * 1996-02-16 1998-10-27 International Business Machines Corporation Servo error detection in a noisy environment

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1210147A (fr) * 1982-03-18 1986-08-19 Hiroshi Yoshioka Dispositif de centrage
JPS59161555U (ja) * 1983-04-14 1984-10-29 日本ビクター株式会社 トラツキングサ−ボ回路
JPS60138753A (ja) * 1983-12-26 1985-07-23 Sony Corp デイジタル信号の記録再生方法
JPS60209952A (ja) * 1984-03-31 1985-10-22 Toshiba Corp トラツキング装置
JPS6166250A (ja) * 1984-09-07 1986-04-05 Sony Corp トラツキング制御回路
JPS62214543A (ja) * 1986-03-14 1987-09-21 Toshiba Corp ヘリカルスキヤン方式テ−プ再生装置のトラツキング制御回路
JPS6318565A (ja) * 1986-07-11 1988-01-26 Pioneer Electronic Corp デジタル信号記録再生装置

Also Published As

Publication number Publication date
US5003413A (en) 1991-03-26
DE68922051T2 (de) 1995-12-21
EP0359019A3 (fr) 1991-09-04
DE68922051D1 (de) 1995-05-11
JPH0271419A (ja) 1990-03-12
JPH0740340B2 (ja) 1995-05-01
KR900005385A (ko) 1990-04-14
EP0359019A2 (fr) 1990-03-21
KR920006621B1 (ko) 1992-08-10

Similar Documents

Publication Publication Date Title
US4714971A (en) Method and apparatus for reproducing signals having improved rotary head tracking control
EP0359019B1 (fr) Circuit de commande de suivi de piste pour un appareil à bande magnétique à balayage hélicoidal
GB1535914A (en) Reproduction of a recorded signal
US4755893A (en) Tracking control apparatus using pilot signals and position detecting signals of various lengths
JPS6321247B2 (fr)
US5182681A (en) Rotating head magnetic recording and reproducing device having automatic tracking control function
EP0227468B1 (fr) Appareil d'enregistrement et/ou de reproduction
EP0436114B1 (fr) Circuit de commande de suivi de piste
EP0067562B1 (fr) Appareil de reproduction magnétique
CA1118886A (fr) Alignement automatique pour magnetoscope
US4920435A (en) Magnetic recording and reproducing device with improved track servo
US5055952A (en) Automatic track finding (ATF) controller for digital audio tape recorder
US5490017A (en) Signal reproducing apparatus
GB2095434A (en) Information signal recording and reproducing apparatus
US4432026A (en) Apparatus and method for determining read head position
US5026509A (en) Tracking control system for information reproducing apparatus
US5089918A (en) Magnetic recording and/or reproducing apparatus having single head with two gaps and providing different lead angles in different operating states
US4860130A (en) Rotary head type digital audio signal reproducing apparatus
EP0316954B1 (fr) Méthode de reproduction pour enregistreur à bande du genre à téte rotative
KR100275058B1 (ko) 기록 재생 장치
US4743921A (en) Information signal reproducing apparatus having a tracking control system
KR960012999B1 (ko) 브이씨알의 헬리컬 헤드 트래킹 장치
US4878134A (en) Information signal recording apparatus for aligning helical slant tracks
JP3271198B2 (ja) Ｄｔヘッドのトラックずれ量検出装置
KR0181071B1 (ko) 비디오 카세트 레코더의 트랙킹 방법

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19890828

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): DE NL SE

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): DE NL SE

17Q First examination report despatched

Effective date: 19930105

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE NL SE

REF Corresponds to:

Ref document number: 68922051

Country of ref document: DE

Date of ref document: 19950511

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 19980806

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19980827

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19980907

Year of fee payment: 10

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19990830

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20000301

EUG Se: european patent has lapsed

Ref document number: 89115859.4

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 20000301

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20000601